Are whip spring lines supposed to be tight?

[lostpacket]

I'm doing the "m" setup right now and the middle cleat just runs through it but the ends are tied...is this right or should they all be loose?

 

[SEMPERFI8387]

I never keep my lines tight. I found out it can cause my fenders to roll up onto dock. I leave play so my boat can move freely vs. the dock.